Lewis Choy, Parulkar Suraj D, Bebawy John, Sherwani Saadia, Hogue Charles W
Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, IL.
Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, IL.
J Cardiothorac Vasc Anesth. 2018 Oct;32(5):2313-2322. doi: 10.1053/j.jvca.2018.03.032. Epub 2018 Mar 20.
Neurological complications of cardiac surgery have a large effect on patient outcomes. In this review, the value of several modes of central nervous system monitoring for improving perioperative care is critiqued. The electroencephalogram (EEG) has been used as a means for detecting brain ischemia. Even though EEG changes are specific for ischemia, the reliability is tempered by many confounding factors. The effectiveness of the processed EEG for ensuring amnesia during surgery is controversial, but it may have value for optimizing anesthetic dose and thus reducing the risk for delirium. Transcranial Doppler may be beneficial in confirming flow to both cerebral hemispheres during antegrade cerebral perfusion such as during aortic arch surgery and in detecting cerebral emboli. Transcranial Doppler can be used for monitoring cerebral autoregulation, allowing for individualization of blood pressure targets during surgery. Measures of adequacy of cerebral oxygen balance include jugular bulb venous oxygen saturation and near-infrared spectroscopy monitoring. Both monitors have limitations that reduce the sensitivity for detecting brain ischemia. Because near-infrared spectroscopy-measured regional cerebral oxygen saturation does not distinguish arterial from venous blood, these measurements reflect the adequacy of oxygen delivery versus demand. Over short periods, filtered regional cerebral oxygen saturation data may provide a clinically feasible method of monitoring cerebral autoregulation that overcomes many limitations of transcranial Doppler. Ongoing studies have demonstrated that the latter methodology for determining perioperative blood pressure targets has large potential for reducing organ injury from cardiac surgery.
心脏手术的神经并发症对患者预后有很大影响。在本综述中，对几种中枢神经系统监测模式在改善围手术期护理方面的价值进行了批判。脑电图（EEG）已被用作检测脑缺血的一种手段。尽管脑电图变化对缺血具有特异性，但可靠性受到许多混杂因素的影响。处理后的脑电图在确保手术期间遗忘方面的有效性存在争议，但它可能对优化麻醉剂量从而降低谵妄风险具有价值。经颅多普勒在确认顺行性脑灌注（如在主动脉弓手术期间）时双侧大脑半球的血流以及检测脑栓塞方面可能有益。经颅多普勒可用于监测脑自动调节，从而在手术期间实现血压目标的个体化。脑氧平衡充足性的测量指标包括颈静脉球血氧饱和度和近红外光谱监测。这两种监测方法都存在局限性，降低了检测脑缺血的敏感性。由于近红外光谱测量的局部脑血氧饱和度无法区分动脉血和静脉血，这些测量反映了氧输送与需求的充足性。在短时间内，经滤波的局部脑血氧饱和度数据可能提供一种临床上可行的监测脑自动调节的方法，该方法克服了经颅多普勒的许多局限性。正在进行的研究表明，后一种确定围手术期血压目标的方法在减少心脏手术引起的器官损伤方面具有很大潜力。
